Page 312 - Clinical Manual of Small Animal Endosurgery

300 Clinical Manual of Small Animal Endosurgery

formation, and this further increases the risks associated with a blind-
access approach. Elhage et al. (1996) demonstrated that open access was
statistically significantly safer than blind-access techniques such as the
use of a Veress needle in rabbits with abdominal adhesions, and this
resulted in fewer bowel injuries. The Ternamian EndoTIP cannula also
appears poorly suited to these species, particularly if there are abdominal
adhesions present, as the spiral end can catch and penetrate a section of
gas-distended caecum.
The author’s preference is to use a 4 mm, 30°, 18 cm-long laparoscope
for most small mammals, and a 5 mm, 30°, 30 cm laparoscope for larger
rabbits, as these give markedly more illumination and better visualisation
than a 2.7 mm endoscope. If using an open-access technique it can be
difficult to achieve a 3 mm-sized skin wound for safe insertion of the
primary optical cannula for initial insufflation anyway. One disadvan-
tage of a standard 5 mm endoscope used in canine surgery is that its
length can interfere with the surgeon’s position standing behind the
scope. The laparoscope can alternatively be held by the camera operator
beneath one of the surgeon’s arms.
Diagnostic applications of laparoscopy in small pet mammals are
particularly useful. The large gas-filled caecum in rabbits and hystrico-
morph rodents limits the use of abdominal ultrasound. Useful applica-
tions include exploration of abdominal masses and staging of suspected
uterine adenocarcinomas and other neoplasia and metastasis in rabbit
does. Not all abdominal masses are neoplastic, and well-encapsulated
abdominal abscesses due to a bite from a cage mate are also common in
rabbits and hold an excellent prognosis.
While the main application for small pet mammal laparoscopy in
first-opinion practice is diagnostic in nature, more complex procedures
are also possible (Fig. 10.20). Laparoscopy-assisted procedures can be
especially useful, as the operating space is very small in these patients,
making intracorporeal suturing difficult, even with dedicated 3 mm
needle holders. Some instrumentation used in larger animals is also
unsuitable. Endoscopic staplers are simply too large to insert into even
giant-breed rabbit intestines for anastomosis, or chests for lung biopsy.
The relatively thin body wall in these small mammals also facilitates
laparoscopy-assisted procedures. Techniques such as laparoscopy-assisted
cryptorchidectomy (Fig. 10.21), cystotomy and enterotomy use the same
fundamental techniques as in dogs and cats.
Laparoscopic neutering of female rabbits is possible. Rabbits are pri-
marily neutered to prevent the development of malignant uterine adeno-
carcinomas. These have an extremely high incidence in rabbits, with a
frequency as high as 80% in 5–6-year-old rabbits in one study (Percy
and Barthold, 2001). Unfortunately there is no evidence to demonstrate
that ovariectomy is sufficient to prevent their development, and therefore
ovariohysterectomy distal to the cervix is recommended in rabbits.
Rabbits deposit fat in the uterine suspensory ligaments, making a lapar-
oscopic or laparoscopy-assisted ovariohysterectomy difficult, unless